Davis, U.S. Pat. No. 4,776,845 describes an apparatus that is designed for insertion into the rectum or stoma of a human being. The inventor in Davis U.S. Pat. No. 4,776,845 is the same as the inventor of the present invention. The rectal-stomal insert apparatus described in U.S. Pat. No. 4,776,845 is used during a colonoscopy, wherein a surgeon conducts a visual examination of a patient's colon by the use of remote instrumentation. For the examination procedure, the surgeon utilizes a colonoscope and the rectal-stomal insert apparatus. The colonoscope has a sensing tube that is inserted into the colon. The sensing tube has optical means to provide illumination and viewing of the inside of the colon, and insufflation means for inflating the colon. Inflation of the colon makes the examination easier and reduces the risk of injury.
The rectal-stomal insert apparatus is inserted into the rectum or stoma of a patient before the examination to provide a seal, whereby air pressure for inflating the colon and fecal material are prevented from leaking out. The rectal-stomal insert apparatus is provided with an instrument channel for receiving the colonoscope sensing tube and a suction channel for allowing suctioning of fecal material from the colon. The colonscope sensing tube is inserted into the colon through the instrument channel, wherein the examination can commence.
During a typical examination, the surgeon takes tissue samples of the colon for later laboratory analysis. In the prior art, the surgeon retrieves a tissue sample by inserting a snaring tool into a small (2 mm in diameter) passageway in the colonoscope sensing tube. The snaring tool is pushed through the colonoscope passageway to the end of the sensing tube where it is used to severe a tissue sample from the colon wall. The snaring tool is removed from the colonoscope and a basket retrieval tool is inserted into the colonscope passageway. The basket tool is used to capture the tissue sample. The surgeon removes the colonoscope with the basket tool to retrieve the specimen from the colon. The surgeon then reinserts the colonoscope and resumes the examination of the colon.
When the colonoscope is reinserted, the surgeon tries to resume the examination where he left off, i.e. at the location in the colon where the tissue sample was taken. However, in practice, it is very difficult to relocate the end of the sensing tube in the same spot in the colon from which it was withdrawn. As a result, the surgeon must either reinspect some of the colon, or search for the spot where the specimen was taken. Either way, the process of reinserting the colonoscope is time consuming. Another time consuming aspect of the prior art is the physical removal and reinsertion of the colonoscope every time a tissue sample is taken. What is needed is an apparatus that will allow the removal of tissue during a colonoscopy without having to remove the colonoscope.